The present invention relates to load bearing assemblies, and more particularly to load bearing assemblies for supporting a load bearing surface over an opening with a peripheral frame, such as the seat or back of a chair or bench, or the support surface of a bed, cot or other similar product.
There are continuing efforts to develop new and improved load bearing assemblies. In general, the primary objectives of these efforts are to obtain a durable and inexpensive load bearing surface that is relatively easy to manufacture. In the context of seating and other body-support applications, it is also important to address comfort issues. For example, with seating, it can be important to provide a surface that is comfortable and does not create body fatigue over periods of extended use. Given that the load characteristics (e.g. stiffness, resiliency, force/deflection profile) desired in a particular surface will vary from application to application, it is also desirable to have a load bearing surface that is easily tunable for different applications during design and manufacture.
It is well known to provide load bearing assemblies that include a load bearing surface supported by a frame over an opening. In some applications, such as lounge chairs, a plastic surface is supported over the opening. These surfaces can be durable and inexpensive, but suffer from drawbacks, because thicker plastic materials are rigid and uncomfortable, and thinner plastic surfaces, such as membranes or woven plastic fibers tend to permanently deform (or creep) over time.
More recently, there has been an increasing use of elastomeric fabrics as load bearing surfaces, especially in the seating industry. Elastomeric fabrics can provide a comfortable, ventilated seating structure, and can be tuned to provide a desired amount of elasticity in a particular location. Elastomeric fabrics are typically manufactured from a complex weave of high tech elastomeric monofilaments and multifilament yarns, and often require expensive machinery to stretch and attach the fabrics to a frame. The process results in a relatively expensive surface and, as a result, elastomeric fabrics are not ideal for all applications.
Accordingly, there remains a need for a load bearing assembly that is relatively inexpensive to manufacture while providing a load bearing surface that is both comfortable and durable.